About 13 months after SONY's launch of the A7 series and after uncountable discussions about disappointing corner performance of many 3rd-party rangefinder lenses especially on A7R, the new Zeiss Vario Tessar FE 4/16-35 starts changing the game. Right after launch of the A7, 3D-Kraft was the first site substantiating the excellent performance when attached to the Leica WATE in the article "Ultra Wide Angle M-mount Lenses THAT WORK on Sony A7R". Consequently it is time for another analysis, how the new Zeiss compares to the WATE and while we're at it, I added three more 21mm lenses to that comparison.

The candidates this time were - from left to right (due to a shortage of Sony A7s, the Leica M body had to act as a fifth lens holder ;-)):

Olympus OM Zuiko Auto-W 21mm f/3.5

Voigtlander Ultron 21mm f/1.8 ASPH

Sony Zeiss Vario Tessar FE 4/16-35mm ZA OSS

Leica Wide Angle Tri Elmar (WATE) 16-21mm f/4 ASPH

Leica Super Elmar 21mm f/3.4 ASPH

The Olympus Zuiko 21/3.5 was launched together with the debut of the legendary OM-1. It is a full frame SLR lens with a body length of only 31mm and a weight of 180g. Even with an E-mount adapter, it is still quite a compact solution. The other candidates (except the Zeiss FE 16-35) are M-mount rangefinder lenses, that you find discussed in other articles on this site already.

The comparison was shot with a Sony A7R on a cloudy November day, so contrasts were not too high but for a comparison like this, it allows to seperate good lenses from average lenses even better. All shots were taken from a stable tripod, the shutter was triggered by an infrared remote control. The focus was set manually using the 14.4x magnification in EVF (also the Sony/Zeiss FE 16-35 was focused manually). You can see the "making of" here:

As you may be interested especially in cormer performance, the camera
was turned by a certain degree in both directions and the exposure
compensation was set to +1.7 EV in order to counteract the typical light fall
off towards the edges. All shots were developed from raw with Adobe Camera Raw with identical settings, no lens correction profiles were applied. So you can valuate the distortion and vignetting "as is".

Here you can see as an example the Zeiss FE 16-35 at 21mm and f/8.0:

(click on the image to see other sizes)

As it would be quite boring to show all 86 images here, you can find all shots at varying aperture settings and the Zeiss and the Leica WATE at different focal lengths in full resolution in this Flickr-album:

(click on the image to see the album)

The image descriptions indicate the lens and the setting when you hover over the images in the album.

I extracted the findings that may be most interesting for you into two charts (the charts have a width of 1500 px and the crops are 640x480 px, so please make sure that your display settings / browser zoom settings display them in a correct size).

16mm comparison

The first chart shows the Sony FE 16-35 compared to the Leica WATE at 16mm with four different aperture settings. The first two 100% crops (actual pixels) show the center at f/4.0. As all these lenses are very sharp at the center, these crops are not too exciting. They are primarily meant to give you a reference point for the exposure ath the center allowing you to valuate the light fall off towards the edges.

21mm comparison

The second chart compares all these lenses at 21mm focal length with f/4.0 and f/8.0. Here you see only the 100% crops (actual pixels) from the upper left edge:

Conclusion

The M-mount lenses are vignetting significantly more than the SLR lens and the native E-mount lens but in case of the Zeiss FE 16-35 there was an in-camera-lens compensation applied already to the raw file (see the UPDATE below)

The Leica Super-Elmar 21/3.4 ASPH as the most compact solution also has the strongest color-shift and vignetting. This is a quite typical result for M-mount rangefinder lens used on the Sony A7R, especially if they use a very compact and symmetric design.

The OM Zuiko 21/3.5 does not match the corner sharpness of the WATE or the Zeiss FE but performs quite well and will give you good value for price with acceptable weight and dimensions if you can get a used one in good condition.

At open aperture, the Sony/Zeiss FE 16-35 beats all other lenses and at 16mm it performs best. It delivers high and consistent performance across the whole focal length range only getting a bit weaker at the long end (35mm). It has the least vignetting and the good results at open aperture together with the optical stabilization make it a winner also for videos at low light.

The Leica WATE is still an interesting option with best results at 21mm and f/8.0. It shows that a more telecentric lens design pays off when used on the Sony A7-series.

This was just a first comparison, there will be more samples with the Zeiss FE 16-35 soon, so stay tuned!

UPDATE:Based on hints of some readers I made a quick - not too scientific - comparison between different lens-compensation settings. The Sony A7R (and I assume also all the other models of the A7 series) applies a compensation of about 1 EV towards the edges already to the raw files in order to reduce vignetting. The left image was shot with lens compensation "Auto" for light fall off and color correction whereas the right sample was shot with lens compensation "Off":